A major reform bill to increase competition in Mexico's phone and television markets on Thursday cleared its first hurdle when it was approved by a committee in the lower house of Congress with no changes.

The reform, which aims to curb the dominance of Carlos Slim's America Movil (Mexico City, Mexico) and broadcaster Televisa (Mexico City, Mexico), is expected to be presented to the floor of Mexico's lower house for a vote next week.

America Movil controls about 70 percent of Mexico's mobile phone market and about 80 percent of its fixed lines. Televisa has about 60 percent of the country's broadcasting market.

"We are on the verge of changing the history of telecoms in our country," said Julio Cesar Moreno, president of the committee of constitutional matters that approved the reform.

The constitutional reform, which was unveiled on Monday, will allow foreign companies greater participation in Mexico's phone and television markets and could force players with a market share of over 50 percent to sell assets.